Texas Hospitals Brace for Heat-Driven Cardiac Arrest ICU Surge

As Texas swelters through increasingly frequent and intense heat waves, new preliminary research presented at the American Heart Association's Resuscitation Science Symposium 2026 reveals a direct and troubling link between extreme outdoor heat and a surge in cardiac arrest admissions to hospital intensive care units. The study, which analyzed data from over 11,000 out-of-hospital cardiac arrest (OHCA) patients across 10 U.S. health systems between 2018 and 2024, found that as temperatures climbed above 90 degrees Fahrenheit, ICU admissions for OHCA rose sharply—a finding with significant implications for Texas hospitals, emergency services, and the state's economy.

Researchers discovered that compared with days reaching 85 degrees F, OHCA admissions were 45% higher at 91 degrees F and 102% higher at 98 degrees F. The most vulnerable populations were older adults and women: people ages 65 and older had a 48% higher admission rate for OHCA at 90 degrees F versus 67 degrees F, and women were admitted at a rate 33% higher on days of extreme heat. Cardiac arrest occurs when the heart's electrical system abruptly malfunctions, stopping blood flow to the brain and vital organs; approximately 90% of people who experience OHCA outside a hospital do not survive.

The study's lead author, Peter Graffy, Ph.D., M.P.H., a postdoctoral fellow at the University of Chicago, noted that heat waves place additional strain on communities, emergency services, and hospitals that must absorb the influx of climate-related illnesses. "ICU beds, equipment and staff are limited, and sudden increases in critically ill patients can quickly overwhelm hospital resources if we are not ready," Graffy said. The research found that heat did not significantly impact overall survival or discharge status—a testament, Graffy said, to clinicians' ability to stabilize patients—but the increased demand for critical care interventions such as blood pressure support and continuous dialysis for kidney dysfunction during ICU stays could tax already stretched hospital capacity.

For Texas, where summer temperatures routinely exceed 90 degrees F for extended periods, the findings underscore a pressing need for healthcare systems to adapt. The study's authors suggest hospitals could one day use temperature forecasts in a data-driven way to prepare ICU beds, staff, and resources, coordinating between emergency departments and intensive care units. As Extreme heat is rising – and so is the risk to your heart, according to a July 2026 American Heart Association news release, the public and caregivers—especially those supporting older or medically vulnerable adults—should take heat warnings seriously.

Ashish Panchal, M.D., Ph.D., FAHA, volunteer chair of the American Heart Association Emergency Cardiovascular Care Committee, emphasized that about 70% of cardiac arrests outside a hospital happen at home. "Everyone should learn the lifesaving skills of CPR and seek medical care as quickly as possible," he said. The American Heart Association offers resources such as Cardiac Arrest vs. Heart Attack and the Nation of Lifesavers initiative to help communities prepare.

The research is considered preliminary until published in a peer-reviewed journal, but its implications for Texas businesses and the economy are clear: a warming climate means more heat-related emergencies, higher demand on ICU capacity, and potential disruptions to workforce health. The study will be presented at the About Resuscitation Science Symposium 2026, held Nov. 7-8 in Chicago. For more details, the Link to abstract and the Resuscitation Science Symposium 2026 Online Program Planner are available online. Additional financial information about the American Heart Association is available here.